Exterior windows mounted in the walls of residential or commercial buildings are typically provided to allow for a view of the exterior and the transmission of light into the building. They are also expected to maintain a weather tight barrier against environmental elements such as wind and rain. Preferably, exterior windows offer the capability of being opened for ventilation during favorable conditions.
Originally, most windows used in residential settings were of the guillotine-type wherein there is provided either a fixed upper window portion and a moveable lower window portion or alternatively where upper and lower window portions are moveable. Subsequently, side opening crank-type windows became popular and many suitable mechanisms were developed for opening and closing the windows. One particularly popular type of windows is the so-called sash-type window.
Window hinges are known in the art for providing pivotal movement of the window between open and closed position. Typically, a hinge assembly mounts a window sash to a window frame and controls the opening and closing of the window.
Window hinges typically involve a generally elongated track mounted to the window frame, a sash arm mounted to the window sash and a support arm interconnecting the track and sash arms with the support arm being pivotally connected to both the track and the sash arms.
The sash arm is pivotally connected either directly or by means of an interconnecting link to a mounting shoe that is guided for movement lengthwise along the track. Typically, the sash arm is positioned opposite the track when the window is closed with the inside edge of the sash arm aligning with the inside edge of the track to ensure tight closing of the window.
Although somewhat useful and popular, conventional sash-type window arrangements suffer from some important drawbacks. Some of these drawbacks include that conventional window construction are not well suited to resist the potential for window failure in the event of the window assembly being subjected to certain types of weather condition such as strong winds.
During storms, winds of high velocity typically cause a zone of high air pressure on and adjacent walls of buildings, relative to the air pressure within the building and relative to the air pressure within the sashes of windows located on the walls, particularly if the windows are snugly mounted. The high exterior air pressure typically generates a partial vacuum within the window sashes.
In a strong storm, an exterior window may be subjected to winds in excess of 160 km per hour. Wind loading can be sustained or can occur in gusts and ripples. To withstand such loading, structures require both static and dynamic strength and resilience. Particularly, in the event that the window is subjected to a strong negative pressure, there is a risk that the shoe will be dismembered from the track.
Another main drawback associated with conventional sash-type window assemblies is the difficulty in aligning the window with the window frame. Also, it is often difficult to assemble the pivot assembly to the window frame.
Sash sag first occurs in casement and awning windows when the sash portion of the window is out of alignment with the frame. This misalignment between the window sash and frame can be caused by numerous factors including faulty installation of the window unit, settling of the building, warping caused by weathering or other factors.
A window having sash sag is not properly sealed and will potentially allow wind, moisture and dust to enter the building. This can disrupt the interior temperature and humidity as well as increase the amount of dust and germs. In turn, increased moisture, wind and dust not only disrupt the internal environment but can also cause damage to personal property. Furthermore, if sash sag is not corrected, moisture will seep into the broken seal and cause structural damage to the window frame and the surrounding supporting wall.
The prior art has shown some example of devices for providing adjustment to window sashes in order to correct misalignment with the corresponding window frames. However, such prior art devices are typically labor intensive, often requiring some disassembly of the hinge to make adjustments. This increases the time necessary for adjustment in the cost of producing complex adjustment devices.
Accordingly, there exists a need for an improved window hinge. It is a general object of the present invention to provide an improved window hinge.